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'use strict';
Object.defineProperty(exports, "__esModule", {
value: true
});
exports.default = queue;
var _onlyOnce = require('./onlyOnce.js');
var _onlyOnce2 = _interopRequireDefault(_onlyOnce);
var _setImmediate = require('./setImmediate.js');
var _setImmediate2 = _interopRequireDefault(_setImmediate);
var _DoublyLinkedList = require('./DoublyLinkedList.js');
var _DoublyLinkedList2 = _interopRequireDefault(_DoublyLinkedList);
var _wrapAsync = require('./wrapAsync.js');
var _wrapAsync2 = _interopRequireDefault(_wrapAsync);
function _interopRequireDefault(obj) { return obj && obj.__esModule ? obj : { default: obj }; }
function queue(worker, concurrency, payload) {
if (concurrency == null) {
concurrency = 1;
} else if (concurrency === 0) {
throw new RangeError('Concurrency must not be zero');
}
var _worker = (0, _wrapAsync2.default)(worker);
var numRunning = 0;
var workersList = [];
const events = {
error: [],
drain: [],
saturated: [],
unsaturated: [],
empty: []
};
function on(event, handler) {
events[event].push(handler);
}
function once(event, handler) {
const handleAndRemove = (...args) => {
off(event, handleAndRemove);
handler(...args);
};
events[event].push(handleAndRemove);
}
function off(event, handler) {
if (!event) return Object.keys(events).forEach(ev => events[ev] = []);
if (!handler) return events[event] = [];
events[event] = events[event].filter(ev => ev !== handler);
}
function trigger(event, ...args) {
events[event].forEach(handler => handler(...args));
}
var processingScheduled = false;
function _insert(data, insertAtFront, rejectOnError, callback) {
if (callback != null && typeof callback !== 'function') {
throw new Error('task callback must be a function');
}
q.started = true;
var res, rej;
function promiseCallback(err, ...args) {
// we don't care about the error, let the global error handler
// deal with it
if (err) return rejectOnError ? rej(err) : res();
if (args.length <= 1) return res(args[0]);
res(args);
}
var item = q._createTaskItem(data, rejectOnError ? promiseCallback : callback || promiseCallback);
if (insertAtFront) {
q._tasks.unshift(item);
} else {
q._tasks.push(item);
}
if (!processingScheduled) {
processingScheduled = true;
(0, _setImmediate2.default)(() => {
processingScheduled = false;
q.process();
});
}
if (rejectOnError || !callback) {
return new Promise((resolve, reject) => {
res = resolve;
rej = reject;
});
}
}
function _createCB(tasks) {
return function (err, ...args) {
numRunning -= 1;
for (var i = 0, l = tasks.length; i < l; i++) {
var task = tasks[i];
var index = workersList.indexOf(task);
if (index === 0) {
workersList.shift();
} else if (index > 0) {
workersList.splice(index, 1);
}
task.callback(err, ...args);
if (err != null) {
trigger('error', err, task.data);
}
}
if (numRunning <= q.concurrency - q.buffer) {
trigger('unsaturated');
}
if (q.idle()) {
trigger('drain');
}
q.process();
};
}
function _maybeDrain(data) {
if (data.length === 0 && q.idle()) {
// call drain immediately if there are no tasks
(0, _setImmediate2.default)(() => trigger('drain'));
return true;
}
return false;
}
const eventMethod = name => handler => {
if (!handler) {
return new Promise((resolve, reject) => {
once(name, (err, data) => {
if (err) return reject(err);
resolve(data);
});
});
}
off(name);
on(name, handler);
};
var isProcessing = false;
var q = {
_tasks: new _DoublyLinkedList2.default(),
_createTaskItem(data, callback) {
return {
data,
callback
};
},
*[Symbol.iterator]() {
yield* q._tasks[Symbol.iterator]();
},
concurrency,
payload,
buffer: concurrency / 4,
started: false,
paused: false,
push(data, callback) {
if (Array.isArray(data)) {
if (_maybeDrain(data)) return;
return data.map(datum => _insert(datum, false, false, callback));
}
return _insert(data, false, false, callback);
},
pushAsync(data, callback) {
if (Array.isArray(data)) {
if (_maybeDrain(data)) return;
return data.map(datum => _insert(datum, false, true, callback));
}
return _insert(data, false, true, callback);
},
kill() {
off();
q._tasks.empty();
},
unshift(data, callback) {
if (Array.isArray(data)) {
if (_maybeDrain(data)) return;
return data.map(datum => _insert(datum, true, false, callback));
}
return _insert(data, true, false, callback);
},
unshiftAsync(data, callback) {
if (Array.isArray(data)) {
if (_maybeDrain(data)) return;
return data.map(datum => _insert(datum, true, true, callback));
}
return _insert(data, true, true, callback);
},
remove(testFn) {
q._tasks.remove(testFn);
},
process() {
// Avoid trying to start too many processing operations. This can occur
// when callbacks resolve synchronously (#1267).
if (isProcessing) {
return;
}
isProcessing = true;
while (!q.paused && numRunning < q.concurrency && q._tasks.length) {
var tasks = [],
data = [];
var l = q._tasks.length;
if (q.payload) l = Math.min(l, q.payload);
for (var i = 0; i < l; i++) {
var node = q._tasks.shift();
tasks.push(node);
workersList.push(node);
data.push(node.data);
}
numRunning += 1;
if (q._tasks.length === 0) {
trigger('empty');
}
if (numRunning === q.concurrency) {
trigger('saturated');
}
var cb = (0, _onlyOnce2.default)(_createCB(tasks));
_worker(data, cb);
}
isProcessing = false;
},
length() {
return q._tasks.length;
},
running() {
return numRunning;
},
workersList() {
return workersList;
},
idle() {
return q._tasks.length + numRunning === 0;
},
pause() {
q.paused = true;
},
resume() {
if (q.paused === false) {
return;
}
q.paused = false;
(0, _setImmediate2.default)(q.process);
}
};
// define these as fixed properties, so people get useful errors when updating
Object.defineProperties(q, {
saturated: {
writable: false,
value: eventMethod('saturated')
},
unsaturated: {
writable: false,
value: eventMethod('unsaturated')
},
empty: {
writable: false,
value: eventMethod('empty')
},
drain: {
writable: false,
value: eventMethod('drain')
},
error: {
writable: false,
value: eventMethod('error')
}
});
return q;
}
module.exports = exports.default; |